Evaporator.



P. KESTNER. EVAPOBATOB.

APPLICATION run we. 31. 1906.

965,388. Patented July 26, 1910.

4 anfisms-snnnr 1.

P. KESTNER. EVAPOBA'I'OR. APPLICATION mum .um. 31, 1906.

965,388. Patnted July 26,1910.

4 SHEETS-SHEET 2.

ZM IZessea Jaye-V7797! Zdlll 1295mm; ,3 555' P. KESTNER.

EVAPOBATOB.

APPLIOATION FILED AUG. 31, 1906 965,388. Patented July 26, 1910.

4 SHEETS-SHEET 3.

P. KESTNBR. BVAPOBATOR.

APPLICATION FILED AUG. 31, 1906.

Pdtented July 26, 1910.

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-D s ATns PA FFIoE.

PAUL KESTNEB, F LILLE,FBANCE, ASSIGNOB TO KES'INEB EVAPORA'IOB COMPANY, 01' PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Evnom'ron.

spe i q of Letters t nt. Patented July 26, 1910.

Application filed August 81,1906. Serial No. 382,868.

To all whom it may concern:

Be it known that I, PAUL KESTNER, a citizen of the French Republic, residing at Lille, in the Nord Province of France, have invented certain Improvements in Evaporating Apparatus, of which the following is a specification.

My invention relates to concentrating or evaporating apparatus, and has reference to an improved evaporator to be used for concentratin liquids and is especially useful for such liquids as cause scaling on the heating surfaces and alsofor such liquorsfor example, glue, gelatin, extracts of various kinds and even sugar juices, which are likely to be injuriously 'afiected if allowed to remain for any length of time in stationary contact with a heated surface.

The objects of my invention are to prevent or at least considerably reduce the amount of such scaling and also to enable those parts of the evaporator in which the scaling takes place to be from time to time cleaned without interfering toany material extent with the process of evaporation and concentration carried on.

By means of my improved evaporator other advantages are also attained which will hereinafter be referred to.

- My improved evaporator consists for each efl'ect of a plurality of elements comprising a main element and secondary elements, thelatter of which are so connected with the former that steam admitted into the main element will also enter the secondary elements so as to impart the required heat to all the elements for the concentrating process. Each of the secondary elements 13, further, so connected with the main element that the liquid to be concentrated will circulate through both and preferably. also so that the vapor evolved'in the secondary elements will so enter the main element as t prevent priming therein.

In the accompanying drawings: Figure 1, shows an evaporating apparatus embodying my invention, comprising a main element and two secondary elements; Fig. 2, is a sectional view of the mainand one of the secondary elements; Fig. 3, is a'view in elevation of a structure made in accordance with my invention, showing a triple efli'ect evaporating apparatus, with each eifect of which the additional or secondary element has been combined Fig. 4:, is a plan view of the apparatus shown in Fig. 3; Fig. 5, is a sec-- tlonal view of one of the main and secondary elements of the structure shown in Fig. 3, and Fig. 6, is a view illustrating an ordinary quadruple eifect evaporating apparatus, wlth the first effect of which one of the secondar evaporating elements has been combine v In operation, vacuum pans of the ordinary designs often prove lnefi'ecient for various reasons. If not well designed, 'circula tion is apt to be defective, dead air spaces exist where air accumulates and prevents access of steam and deranges its normal circulation, or entrainment is excessive. Further, it is often desirable to add additional evaporative capacity to an existing plant without remodeling the old apparatus or sacrificing additional floor space.

' It is the object of my invention to obviate the noted defects andtsecure the stated advantages. To this end, I add to the old type pans certain novel and peculiar auxiliary evaporating devices whereby liquid and steam circulation are made positive and automatic, even in badly designed pans, and

entrainment is prevented, and whereby the evaporative capacity of the'plant is enormously increased. In my'invention, the old pans have connected with them a tube nest of relatively long narrow tubes in a steam chamber adapted to draw its steam supply from near the top of the steam chamber of the ordinary pan. This connection prevents air accumulating in the top of the chamber of the ordinary pan while by reason of the narrow diameter of the secondary pan vapor velocities therein are too great to permit the steam chamber becoming air bound. By connecting the vapor delivery of the auxiliary or secondary pan to the vapor space of the first pan in the hereinafter described manner,circulation in the first pan is much improved and entrainment suppressed. By reason of the relatively long and narrow form of the auxiliary pans, they may be directly attached to the ordinary pans, without use of floor room, and, with multiple effects they may be advantageously placed in the angles between the several eifects.

The improved form of evaporator which I have combined with the old type of concentrating apparatus employing vacuum pans in single or multiple effect, relates to preferably in the form of steam is admitted to reduce the water content of the liquid under process of treatment. This apparatus is based upona novel method of circulating the liquid to be concentrated, whereby it is caused to rise within said tubes, from bod f li uid fed to the bottom of the a y 0 q by liquidpi es f and e,- the former ,of which.

same, in a series of ascending films clinging to the inner surface of such tubes, such films being caused by the presence of steam from said liquid, which carries the latter in P6 a thin stream in a more or less concentrated condition to the top of said tubes where the liquid is caught and may be passed to an other structure employing a similar set of tubes or otherwise disposed of, and wherein the steam is passed through a separator whereby the liquid entrained therewith may be removed; the steam passing to the next efl'ect, or disposed of as may be desired. In the present application of this system the liquid and vapor is returned to the main pan. This evaporating system is based on the theory that when in a tube, no matter what may be its position and its diameter,

i and: wherein a current of vapor is formed in an amount suflicient to flow with a velocity equal to or above twenty-two feet per' second, we admit a small quantity of liquid, this liquid will be forced along the internal walls of the tubein a thin uniform layer,

though traveling with a velocity relatively slow, which depends on physical'conditions, such as density, viscosity, etc. If the tube be vertical and the circulation takes place from the bottom toward the top, the phe;

nomenon takes the form which I have termed creepage; that is to say, the apparatus operates with substantially empty film lined-tubes, receiving from a feed pipe,

controlled .by a suitable valve only that quantity of liquid that may be concentrated to the desired point in a single passage through the tubes, from the bottom to the In the drawings herewith, A is the main element of well known construction and B the secondary elements, the latter being-of considerable length compared with the former and arranged relatively thereto about as shown, that is to'say, the secondary elements reach at their upper ends to substantially half way up the main element and their lower ends extend to considerably below that of the main element. The main element is provided at its lower part with vertical tubes a of suitable dimensions and a central tube a';of comparatively large diameter; the said tubes being carried in tube plates 31 in the usual manner. The ele-.

ce ses ments B are also provided vertical tubes carried in tube plates but'which tubes extend for the greater part oi the. length of the elements and the elements'B are .oon-

nected to the element A by. pipes 0 so that when steam is admitted through a cock (1 .to surround and heat the tubes a steam will also flow into and heat the tubes within the shell of each element B; any condensed water bein got rid of in the usual manner by draw-o cocks or otherwise.

The elements A and Bare also connected lead from t '6 lower part of A into the bottom of B, and-the pipes e lead' from theupr end: ofB into the element A at a suit able height above the tubes (1. 'The elements when steam is a mitted around the tubes in A andein B, the'said liquid will be caused to circulate; rising up the-element B thentlowing into the element A then circulating therein and .finally descendin through thepipeor pipes f back into the ottom ofthe secondary elements B.

the element A, I

To prevent priming in lead the pipes e tangentially thereinto so A andB havin been supplied with liquid that the vapors passing from the secondary elements B into A will be causedto-inove in takes place. on that heatingsurface of theevaporator with which the thin liquid is in contact and in order that I may, without interfering-with the continuity of the evaporating) process, clean the parts when they have liquidr'into the secondary elements B (for ecome'scaledl may introduce the thinmeans whereby any one of these secondary elements may be cut out. Thisar-rangement results in a complex s stem of circulation. -In'addition to the or inary up and down circulation inpan A. caused by the difiereiitial heating 0 the liquid in the wide and narrow vertical tubes, thereis a cyclic circulation betweenthe two pans, liquid from 'A descending through pipe f, thence upward through the auxiliary pan B, and' back to A,

together with generated vapors, through e;

this circulation being ordinarily somewhat assisted by the surface cooling of pipe f by the air. Further, since pipe 0 dischar es tangentially into A above the liquid leve a number of new results are accomplished.

The va ors' form a whirl which tends to throw t e acoompanyingliquid by centrifugal actionoutward against the pan wall, thence to-trickle downward into the main body of liquid, and which destroys the ordinary the liquid in A. In any boiling:

vertical upward stream of vapor from the ordinary {wardor entrained by t 1i a1,- a; the instant atbubble' breaks it throws upward a'dropletbf liquid which in vacuum of vapor, necessitating special devices in the.

-vapor line to collect and return entrained ."liquid. With the tangentiall instreami'n current ofvapor these drop ets inlieuo being carried upward are whirled .against the lde of the pan. 'Agai'mthe whirl of the 'vapor's produces a corresponding movement of the surface liquidin the an which much facilitates evaporation and I --d'ownward circulation through th central tube a. The natural form of ward, the cross bafiie' plate shown acts to suppress any possible central upward movement of entramed li uid. With the-liquid fed into the base of t e auxiliarypan B,'as

' is preferably done, it receivesits first neatmg and evaporation therein, and deposits v whatever scale forming bodies it carries in which is impossible with the ordinary type of vacuum an, as -for instance' an A. Op-- erating in t e manner describe all or most of the scale is deposited in pan B and pan A can consequently run for long periods of time without cleaning.

-In Figs. 3, 4 a d 5, I have illustrated an evaporating apparatus. of tri le effect, in

which the arrangement of vertlcal evaporating tubes under the creepage system and.v

forming the secondary elements, have been applied to each efl'ect. .The ordinary vacu- -.um pans areindicated. at A, A, and'A",

while the secondary or supplemental evaporators are'indicated at B, B and B In within the structure B coupled with the second effect, is fed by means Of'fl pipe g extending from a point substantially at the level of the body of liquid in the vacuum pan'A to the usual inlet at the bottom of said vertical tubes. In this form .o'f-combined' ap aratus embodying my invention, the'cham r at the base .of the element'B therein may be provided with a valve. designed to throttle the feed and insure that only that quantity of liquid'which may be brought to the desired density in a single passage through said tubes is fed thereto,

and for the other sets of evaporating tubes .in the elements B and B I may provide similar valves or those of self-regulating yp I The entrained liquid and steamrising in the vertical tubes within the structure B enter the pan A through 'the pipe 8, whose ,openin into said an A is disposed'tan- .gentia y, so that t e incoming volume of ans, is carried or-- e uprushmg current als aids the p a gaseous; whirlpoolbelng with the cone pomtmg up-' .motion and e'fiect a separati'onfof the 'liqui from the steam.. The separated ste m passes this separationthe pan ,A is'provided with a baflle-plate h sl'iitably supported within t e ulpEer chamber of said an and providcient spacebetween its edge and-the mgls ,wa of the pan to permit the-passage of, the

se arated steam.

shown in Fig.2; indicating the relative rup eefi'ect, in which the structure having the elongated vertical evaporating tubes has been applied "to the =first effect only. The connections, and the method of 'o eration are substantially the same as that escribed with relation to the structures of the other figuresof. the drawings; the purpose o-f'this view being to indicate the ready application 0f the improved apparatus to evaporating structures already in use. 5

- 1.- An evaporating apparatus, comprising 1g. 4,-'1 s. a plan view of the structure osition of the. various parts of thefcomined apparatus, and Fig. 5, is a sectional view of oneof the main and secondary elements of the same. r The structure-illustrated F ig.- 6, shows. sim ly an evaporating apparatus of quadan evaporating pan adapted to contain and evaporate a body of liquid, and means for withdrawing and evaporating a portion of the liquid from the base of said pan, evaporating the same in an auxiliary pan inliquid and vapor communication :with the main pan and returning saidliquid with resultant vapors tangentially into said main pan above the level of liquid therein. this instance, the series of vertical tubes 2. Aneva porating apparatus, comprising an evaporating panadapted to contain and evaporate abody of liqu1d,'and an auxiliary evaporating pan in liquid communication at its base with theifirst pan and provided at its upper .endwith means fordischarging tangentially into said pan above the level of liquid therein the liqu d evaporated'in said .auxiliary'pan with its resultant vapors. communicating with the set of vertical tubes evaporate .a body of liquid, an auxiliary evaporating pan comprising a steam chamber with upright'tubes disposed therein, a connection deliverin liquid from the first pan into the. base 0 said tubes, and a connectiohfidelivering liquid and vapor from the upper end of the tubes tangentially into the first pan above the level of liquid therein.

4. An evaporating apparatus, comprising a vapor heated evaporating pan adapted to contain and-evaporate a body of liquid, an auxiliary evaporating pan comprising a heating chamber with elongated vertical tubes a iaposed was a'f'zconneoti'on lietweon-theheatingelemnts of'flhefirst an ands-the heating chamber or the secon aconnection deliverin o-liquid's from; the first v .5 ut into the baseo the. vertical tubes, and 'a conneotiondelivering' liquid: and vapor from the upper endthe. tubes into the first an; above the levelzef liquid therein.

t in en: evaporating apparatus, the com-.

-m;binition ..o a vacuum panavmg-an evapora'ti'ng space substantially tWlOB as high. as:

. its "diameter, and an auxiliary evaoratorcomprising-a series-f long,-- vert1ca y diseheated-utubes extending. some: 'stance low-said vacuum an and: m liquid connec en-at their base with said: pan,

evaporator being arranged. to discharge. from the upper endsof its tube's1 i vapor {andfluid tangentially into" the va or q -spaoeqof said'vacuumpan. above the lev :of! "liquid; thnreim. p 6:112; an: evaporating apparatus, a closed, provided withiii-horizontal, plate a Q for-'=introducin a tan ntial vapor 'currentl intothe-pan beow sai aha-file plate. 7..- In evaporating apparatus, the co'mbi-= nation of. a; closed: vacuum pan; for contain-4 ing a. relatively large body}. of; liquid. and; having a relatively small heatingsurface,; an auxiliary evaporator for containing. a, relatively small ro rtion of. liquid-and havinga; relatiyey. afige heating surface "said-auxiliaryevaporator comprising ase-.- -1i8S '0 elongated vapor heated-tubes disposed ext'eriorlfieof said vacuum pan, a casmg or saidf tu I sin va or connection Wlthi the heating "-'el ements o the ,vacuum pan',g

and a connection between the liquid spaces ofi said vacuumpan and auxillary evap-g orator.-- 8.- In an evaporating-i apparatus, the combinationof a closed vacuum pan, an auxiliary evaporator comprisinga series of 'va --heated tubes.from which ascendin bo ies of vapor and liquid are discharged into the vapor space of the vacuum pan: abovethe-level of liquid therein, and-means for feeding liquid to the base'of said tubesforascenslon-therein, and a connection betweena the liquid spaces ofsaid vacuumpani and auxiliaryevaporator; o

92 In} an evaporating apparatus, the'combihationofamain evaporating pan closedi to tlie atmosphere, an auxiliary evaporator comprising a casingin which is mounted al series of va or heated tubes delivering as-- i cendingbodmsof liquid and vapor into-the; v or space of said closed pan above the leyel of liquid therein, said auxiliary evap-= orator havingcommunication at its base with the-liquid space in the main evaporating pan, revision for the inlet-- of fiOSlll liquid to t 'e-baseof 'said auxiliary evapora-- T ter; andaconnection between the heating ve the liquidtlevel',.and means! s'pa'o'es-of said main and evaporators. 3 '3' 10; In an evaporating apparatus, the combination ofia closed-evaporating pan,

an auxiliary evaporator comprisin a series of relatively long vaor-heate "tubes :having their up or ends a ove the normal =liq1iid= levelof t e first pan, said tubes de-4 l-iv'ering ascending bodies of liquid and; vapor tangentially into the v or space of said pan above the level of llquid therein and means; for feeding liquid to the" base oi said tubesfor ascension therein.) I 1 1 1' In: an evaporating apparatus, the combination ofan evaporating paneontain- :ing-aseries of vertical passages, said passages comprising a-series of narrow tubes encircling. a central wider tube, means for 'dischar ng acurrent of vapor'and'liquid. tangentially into the vapor s aceot said -panat a point above the norma liquid level I therein, and means.- for supplying a heating mediumt'o-said pan. a

12; an evaporatin apparatus, the combination ofa pair -*0 evaporating "pans ihavin'g vapor connection between their heating elements, and a liquid connection between their liquid containing chambers, one of said pans having tubes of relatively ;short length, -'while the other panhas tubes 0f greater length, the upper ends of which latter tubes are at a point above-the normal level of liquid-in the first pan whereby liq- --uid' and-resultant vapors mabe'discharged ;into the vapor space of sai first pan, the connection between such elements providing for the inlet of said liquid and vapor in a tangential path. I 1

13; Iman evaporating a paratus, the combination of a vapor lieate evaporating pan, andan auxiliary evaporator of 1 relatively small volume having a series of narrow {elongated vertically disposed vapor-heated tubes, said tubes bein In liquid and vapor communication with t 'e first panfand said auxiliary evaporator drawing vapor for heating from t e upper-portion of'the-vapor chamber of" said first pan. 14. Inanevaporating apparatus, the combination of a main-evaporatin element comprising a closed pan, a plura ity of secondary evaporating elements so connected to the mainelement that liquid to be concentrated may circulate upwardly through each of the secondary elements 'and be discharged-- .-therefrom-- into themain element for passage downwardly throu h the latter and en sequent passageto t e secondary ele iments, connections between" the liquid'spaces of said'main and secondary elements, and imeanswherebysaid secondary elements may be placed out of communication with the rest of the apparatus; a

15; In anaeva crating apparatus, the-com-v bination of. ac osed vacuum pan: having a pan, evaporatin main evaporatin element, a series of circulating tubes in t e lower part of the same, a plurality of secondary eva oratin elements containing a series 0 circu ating tubes of greater length than the tubes of the main element, the upper ends of the tubes of said secondary elements reaching'to a point above the tubes within the main element, liquid and vapor connections between the upper ends of the secondary elements and the main element, liquid connection be tween the base of the main element and the base of the secondary elements, connections for the tween sald elements, the first-named connections opening in the main evaporating element above the normal level of liquid therein whereby the vapors generated in the secondary elements may be discharged tangentially into the vapor space of said main element, and a horizontal baflle plate mounted in said vapor space.

' 16. An evaporating apparatus, comprisin an evaporating pan adapted to contain and evaporate a body of liquid, means for withdrawing a portion of the liquid from said the same in an auxiliary pan in liquid an vapor communication with the main pan and returnin resultant vapors tangential y into said main pan, and a horizontal bafile plate within the vapor space of the main pan below which said liquid and vapor is discharged.

17. In an eva crating apparatus, the combmation of a c osed vacuum pan provided passage of a heating medium be-.

said liquid with with a horizontal bafile plate above the level of liquid therein, an auxiliary eva orator comprising a series of vapor-heate tubes extending some distance below said vacuum pan, and a connection between the upper end of said auxiliary evaporator and the closed vacuum pan for delivering vapor and liquid into the vacuum pan below said baffle plate.

18. An evaporating apparatus, comprising a closed evaporating pan having a horizontal baflle-plate within its vapor space above the level of liquid therein and adapted tocontain and evaporate a body of liquid, and an auxiliary evaporating pan in liquid communication at its base with the first pan and provided with means for dischar ing vapors generated therein tangentially into the first panbelow said baffle-plate.

19. In'an evaporating apparatus, the combination of a closed vacuum pan provided with a horizontal baflle-plate above the liquid level, and an auxiliary evaporator in liquid and vapor connection therewith, said auxiliary evaporator comprising a series of vapor heated tubes in vapor'connecti'on with the heating elements of the vacuum pan, and discharging liquid and resultant va or tangentially into said pan below the baiEe-plate.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

, PAUL KESTN ER.

Witnesses:

CHARRIER LEIN, LEN PECKEL. 

